So Phelps entertained him with a quick story about how he knew the expression would catch on even as he was making it.

“The worst is I was sitting in the ready room,” Phelps recalled. “I always know there are two cameras before we walk out. I’m sitting there spitting water, like what is going on? And as I’m making a face, I’m like, yup, that’s on camera … Someone will pick that one up tomorrow.”

Then Fallon pulled out a cardboard cutout of the “maddest face” Phelps rocked in Rio, which got some good laughs.

The “Tonight Show” host also took the opportunity to tease the Olympic swimmer about how he “didn’t get the memo” regarding Ryan Lochte’s activities in Rio.